Sixteen militants were killed and 34 were arrested in a major crackdown in the Sinai Peninsula launched by Egypt on Friday, the army said on Sunday.
Army spokesman Tamer Al Rifai said the extremists had been killed and detained during a "sweep and raids ... in northern and central Sinai".
"The air force targeted and destroyed 66 targets used by terrorist elements to hide from air and artillery attacks," for shelter during raids by security forces, he said in a statement. He added that 11 pickup vehicles and 31 motorbikes were destroyed.
The air force also discovered and destroyed an explosives-making laboratory and a communications centre, as well as six cannabis and opium fields, he said.
Egyptian president Abdel Fattah El Sisi — who is seeking re-election next month — pledged in November to wipe out terrorist elements “within three months” after militants killed more than 300 people at a mosque in the village of Al Rawdah, in the troubled northern sector of the peninsula near Bir El Abd town. No group has claimed responsibility for that attack.
Read more: Egypt's Operation Sinai 2018 is all-out war on militants
In December, militants launched another attack, firing a missile at a helicopter that was part of the entourage of Egypt's defence and interior ministers, who were in the provincial capital El Arish on an unannounced visit. Neither minister was in the aircraft when the attack took place but the missile killed an officer and wounded two others.
Egypt's security forces have been increasingly targeted by extremists since the army in 2013 overthrew Mr El Sisi's predecessor, president Mohammed Morsi.
A military spokesman earlier said that "Operation Sinai 2018" would cover large parts of Sinai, but also parts of the Nile Delta and the Western Desert, where other militants have waged attacks, some believed to be staged from neighbouring Libya.
The offensive comes ahead a March vote that will undoubtedly see Mr El Sisi win a second four-year term.